Early stages of collective cell invasion: Biomechanics

TL;DR

This paper introduces a novel fractional step cellular Potts model to simulate early collective cell invasion, capturing different invasion modes and the effects of active forces with improved realism over traditional methods.

Contribution

The study develops a fractional step cellular Potts model that accurately simulates early collective invasion modes, incorporating active forces and stiffness gradients with enhanced realism.

Findings

Fractional step method yields more realistic invasion scenarios.

Active forces and durotaxis influence invasion dynamics.

Model sets groundwork for future biochemical integration.

Abstract

The early stages of the collective invasion may occur by single mesenchymal cells or hybrid epithelial-mesenchymal cell groups that detach from cancerous tissue. Tumors may also emit invading protrusions of epithelial cells, which could be led (or not) by a basal cell. Here we devise a novel fractional step cellular Potts model comprising passive and active cells able to describe these different types of collective invasion before cells start proliferating. Cells moving toward stiffness gradients (durotaxis) and active forces pulling them away from the tumor have different symmetry properties under cellular extension and retraction that sometimes hamper collective invasion when put together. Thus, these forces are included in different half steps of the fractional step method. Compared with a single step method, fractional step produces more realistic collective invasion scenarios with little extra computational effort. Biochemical mechanisms that determine how cells acquire their different phenotypes and cellular proliferation will be incorporated to the model in future publications.